Definition: You are given a question on US foreign policy. You are also given 4 answer options (associated with "A", "B", "C", "D"), out of which only one is correct. You need to answer the question by selecting the correct option. You should only answer with the choice letter, not the whole answer.
Input: Who is considered the “father” of containment?
(A)George Kennan (B)John Foster Dulles (C)Henry Kissinger (D)Dwight Eisenhower

A